President Obama speaks to reporters at the White House on Friday. / Charles Dharapak, AP

by Susan Davis and David Jackson, USA TODAY

by Susan Davis and David Jackson, USA TODAY

Congress is down to the last day - with no fiscal cliff plan to vote on, at least not yet.

Senators failed Sunday to come up with a bipartisan proposal to head off a series of tax hikes and spending cuts set to start taking effect Tuesday. The White House served notice it may push its own plan and dare Republicans to oppose it.

"Republicans will have to decide if they're going to block it, which will mean that middle-class taxes do go up," Obama said on NBC's Meet The Press.

Optimism rose and fell throughout the day as officials from Capitol Hill to the White House dickered over budget details, worked the phones, spoke with reporters - and generally blamed each other for the impasse over a deal to avert higher taxes on all Americans, massive cuts to major programs and a possible recession as a result.

"Something has gone terribly wrong when the biggest threat to our American economy is the American Congress," said Sen. Joe Manchin, D-W.Va.

The day began with the Meet the Press interview in which Obama said he remains hopeful of a deal, but he made it clear he would hold Republicans responsible if the nation goes over the fiscal cliff.

"The way they're behaving is that their only priority is making sure that tax breaks for the wealthiest Americans are protected," Obama said.

If necessary, Obama said, he would push for a vote on a pared-down plan that includes a renewal of unemployment insurance and an extension of the George W. Bush tax cuts for middle-class Americans who make less than $250,000 a year.

All the Bush tax cuts are set to expire Tuesday. Senate Majority Leader Harry Reid, D-Nev., who spoke with Obama by phone during the day, said he may put such a plan on the floor when the Senate reconvenes Monday.

"If Republicans don't like it, they can vote no," Obama said.

Republicans pointed the finger right back at Obama.

House Speaker John Boehner, R-Ohio, said Obama has always emphasized tax hikes ahead of spending cuts, especially when it comes to the fast-rising entitlement programs of Social Security and Medicare.

"Americans elected President Obama to lead, not cast blame," Boehner said in a statement.

On the Senate floor, McConnell said he called Vice President Biden "to see if he could help jump-start negotiations on his side." The Republican leader noted that he and Biden have worked well together during previous budget battles.

The White House did not comment on the McConnell-Biden connection, and the vice president did not travel to Capitol Hill.

As the evening approached and temperatures fell, so did optimism for a deal. As Reid adjourned the Senate early Sunday evening, he said, "We are apart on some pretty big issues."

During the negotiations, McConnell said, "I'm concerned with the lack of urgency here. There's far too much at stake.

"There is no single issue that remains an impossible sticking point," he said. "The sticking point appears to be a willingness, an interest or courage to close the deal."

Once again, the conflict between the Democratic president and the Republican House has shadowed a budget dispute.

It happened during the near-government shutdown in the spring of 2011. It happened again that same year when the government nearly defaulted during a dispute over the debt ceiling.

As in those previous disputes, the fiscal cliff talks revolve around taxes and spending cuts that could help reduce a federal debt that exceeds $16 trillion.

Obama and the Democrats have emphasized higher tax rates on the wealthiest Americans. Republicans have balked at tax hikes and emphasize spending cuts instead.

Despite their opposition, Republicans pretty much expect that taxes on wealthier Americans are going to rise.

"The president won. The president campaigned on raising rates, and he's going to get a rate increase," Sen. Lindsey Graham, R-S.C., told ABC. But "this deal won't affect the debt situation."

In his NBC interview, taped Saturday, Obama said he has offered Republicans a concession that would reduce Social Security spending by changing the way cost-of-living increases are calculated.

Obama's aides proposed an agreement that would reduce the deficit by $2.4 trillion over 10 years, about half in spending cuts.

"The offers that I've made to them have been so fair that a lot of Democrats get mad at me," Obama said.

Managing the fiscal cliff is essential to improving the economy, the president said. The nation is poised to improve economic growth in 2013, he said, "but what's been holding us back is the dysfunction here in Washington."